Unmanned aircraft vehicle state awareness

Abstract

Methods and systems are described for increasing the safety of unmanned vehicles. Failure rates of components can be combined and adjusted if necessary given sensor data or statistical or historical data that impacts failure rates. The failure rates of components can be combined to give an overall failure or success rate for a vehicle and can be compared to an accepted failure or success rate in connection with a hazard. Hazards with heightened safety requirements can be avoided by a contingency maneuver if the unmanned vehicle's failure or success rate is not acceptable.

What is claimed is: 
     
         1 . A method of operating an unmanned vehicle comprising a vehicle management system (VMS), comprising:
 receiving, by the VMS, a travel plan identifying one or more critical elements along the travel plan;   collecting, by the VMS, sensor data from one or more sensors of the unmanned vehicle, wherein the sensor data indicates a change in a pitch angle of the unmanned vehicle;   calculating, by the VMS a probability of failure based on the sensor data and statistical failure data;   comparing, by the VMS, the probability of failure to a specified probability;   if the probability of failure does not satisfy the specified probability, activating a contingency plan, and if the probability of failure satisfies the specified probability, continuing the travel plan; and   determining that the change in the pitch angle is caused by a partial or whole loss of power in a rotor assembly of the unmanned vehicle.   
     
     
         2 . The method of  claim 1 , wherein the one or more critical elements comprise one or more airspaces around one or more locations. 
     
     
         3 . The method of  claim 2 , wherein the one or more locations comprise a school with a lower specified probability than that of other of the one or more critical elements. 
     
     
         4 . The method of  claim 2 , wherein the one or more locations comprise a city with a lower specified probability than that of other of the one or more critical elements. 
     
     
         5 . The method of  claim 1 , further comprising determining one or more problems in the one or more components based on the sensor data, wherein the probability of failure is calculated by multiplying together one or more component failure rates of the one or more components. 
     
     
         6 . The method of  claim 1 , further comprising updating at least one of the one or more component failure rates based on the one or more problems. 
     
     
         7 . The method of  claim 1 , further comprising receiving, by the VMS, the statistical failure data. 
     
     
         8 . The method of  claim 1 , wherein the unmanned vehicle comprises an aircraft and the contingency plan comprises flying in a holding pattern. 
     
     
         9 . An unmanned aircraft comprising a vehicle management system (VMS), the unmanned aircraft comprising:
 one or more components configured to assist in operating the unmanned aircraft;   a pitch angle sensor configured to provide sensor data indicating a change in a pitch angle of the unmanned aircraft;   one or more processors of the VMS that are operable to receive the sensor data from the pitch angle sensor, and further operable to access a flight plan comprising identified critical elements along the flight plan;   wherein the VMS is operable to, upon approaching a critical element:   calculate a component failure rate for each of the one or more components using statistical data;   analyze the sensor data to determine if the sensor data mandates an adjustment to the component failure rates;   adjust the component failure rates if mandated by the sensor data;   multiply the adjusted component failure rates to give a net failure probability rate; and   determine that the change in the pitch angle is caused by a partial or whole loss of power in a rotor assembly of the unmanned aircraft;   the VMS further operable to compare the net failure probability rate to an accepted probability, and if the net failure probability rate fails to satisfy the accepted probability, activate a contingency plan, and if the net failure probability rate satisfies the accepted failure probability, continue the flight plan.   
     
     
         10 . The unmanned aircraft of  claim 9 , further comprising a shear stress sensor. 
     
     
         11 . The unmanned aircraft of  claim 9 , further comprising a sensor coupled to a propulsion powerplant of the unmanned aircraft. 
     
     
         12 . The unmanned aircraft of  claim 9 , wherein the one or more components comprise a rotor, a battery, and an actuator. 
     
     
         13 . The unmanned aircraft of  claim 9 , further comprising one or more sensors configured to detect environmental data. 
     
     
         14 . The unmanned aircraft of  claim 9 , further comprising a sensor coupled to an actuator. 
     
     
         15 . The unmanned aircraft of  claim 9 , wherein the VMS is further operable to analyze the flight plan with a physics-based model and produce a failure trajectory describing possible failures related to the identified critical elements. 
     
     
         16 . A flight control system for an unmanned aircraft, the flight control system comprising:
 one or more communication interfaces configured to receive a flight plan comprising identified critical elements;   a pitch angle sensor configured to provide sensor data indicating a change in a pitch angle of the unmanned aircraft;   one or more processors coupled to the one or more communication interfaces and the pitch angle sensor and configured to maneuver the unmanned aircraft, wherein the one or more processors are configured to, upon approaching a critical element:   calculate a component failure rate for each of the one or more components using statistical data;   analyze the sensor data to determine if the sensor data mandates an adjustment to the component failure rates;   adjust the component failure rates if mandated by the sensor data;   multiply the adjusted component failure rates to give a net failure probability rate; and   determine that the change in the pitch angle is caused by a partial or whole loss of power in a rotor assembly of the unmanned aircraft;   the one or more processors further configured to compare the net failure probability rate to a specified probability, and if the net failure probability rate fails to satisfy the specified probability, activate a contingency plan, and if the net failure probability rate satisfies the specified probability, continue the flight plan.   
     
     
         17 . The flight control system of  claim 16 , wherein the one or more processors are further configured to calculate a failure trajectory by analyzing the flight plan with a physics-based model, the failure trajectory describing possible failure events near the one or more critical elements. 
     
     
         18 . The flight control system of  claim 16 , further comprising a shear force sensor. 
     
     
         19 . The flight control system of  claim 16 , further comprising one or more of the following: thermometer, pressure sensor, accelerometer, shear force sensor, current sensor, global positioning system sensor, weight sensor, altitude sensor, fuel level sensor, engine temperature sensor, and compressive force sensor. 
     
     
         20 . The flight control system of  claim 16 , wherein the one or more processors are further configured to return to the flight plan after the contingency plan.